~50-100 x 106 cells for each ChIP were crosslinked with formaldehyde, lysed, and fragmented with a Misonix Sonicator 3000. Following immunoprecipitation with antibody or IgG control, the protein-DNA crosslinks were reversed and DNA was purified and used for the preparation of Illumina sequencing libraries Purified ChIP DNA was used to prepare ChIP-seq libraries using the Illumina TruSeq DNA Sample Preparation v2 kit